seq.c revision 277590 
1/*	$NetBSD: seq.c,v 1.7 2010/05/27 08:40:19 dholland Exp $	*/
2/*
3 * Copyright (c) 2005 The NetBSD Foundation, Inc.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Brian Ginsbach.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: stable/10/usr.bin/seq/seq.c 277590 2015-01-23 18:42:05Z delphij $");
33
34#include <ctype.h>
35#include <err.h>
36#include <errno.h>
37#include <math.h>
38#include <locale.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <unistd.h>
43
44#define ZERO	'0'
45#define SPACE	' '
46
47#define MAX(a, b)	(((a) < (b))? (b) : (a))
48#define ISSIGN(c)	((int)(c) == '-' || (int)(c) == '+')
49#define ISEXP(c)	((int)(c) == 'e' || (int)(c) == 'E')
50#define ISODIGIT(c)	((int)(c) >= '0' && (int)(c) <= '7')
51
52/* Globals */
53
54static const char *decimal_point = ".";	/* default */
55static char default_format[] = { "%g" };	/* default */
56
57/* Prototypes */
58
59static double e_atof(const char *);
60
61static int decimal_places(const char *);
62static int numeric(const char *);
63static int valid_format(const char *);
64
65static char *generate_format(double, double, double, int, char);
66static char *unescape(char *);
67
68/*
69 * The seq command will print out a numeric sequence from 1, the default,
70 * to a user specified upper limit by 1.  The lower bound and increment
71 * maybe indicated by the user on the command line.  The sequence can
72 * be either whole, the default, or decimal numbers.
73 */
74int
75main(int argc, char *argv[])
76{
77	int c = 0, errflg = 0;
78	int equalize = 0;
79	double first = 1.0;
80	double last = 0.0;
81	double incr = 0.0;
82	struct lconv *locale;
83	char *fmt = NULL;
84	const char *sep = "\n";
85	const char *term = NULL;
86	char pad = ZERO;
87
88	/* Determine the locale's decimal point. */
89	locale = localeconv();
90	if (locale && locale->decimal_point && locale->decimal_point[0] != '\0')
91		decimal_point = locale->decimal_point;
92
93	/*
94         * Process options, but handle negative numbers separately
95         * least they trip up getopt(3).
96         */
97	while ((optind < argc) && !numeric(argv[optind]) &&
98	    (c = getopt(argc, argv, "f:hs:t:w")) != -1) {
99
100		switch (c) {
101		case 'f':	/* format (plan9) */
102			fmt = optarg;
103			equalize = 0;
104			break;
105		case 's':	/* separator (GNU) */
106			sep = unescape(optarg);
107			break;
108		case 't':	/* terminator (new) */
109			term = unescape(optarg);
110			break;
111		case 'w':	/* equal width (plan9) */
112			if (!fmt)
113				if (equalize++)
114					pad = SPACE;
115			break;
116		case 'h':	/* help (GNU) */
117		default:
118			errflg++;
119			break;
120		}
121	}
122
123	argc -= optind;
124	argv += optind;
125	if (argc < 1 || argc > 3)
126		errflg++;
127
128	if (errflg) {
129		fprintf(stderr,
130		    "usage: %s [-w] [-f format] [-s string] [-t string] [first [incr]] last\n",
131		    getprogname());
132		exit(1);
133	}
134
135	last = e_atof(argv[argc - 1]);
136
137	if (argc > 1)
138		first = e_atof(argv[0]);
139
140	if (argc > 2) {
141		incr = e_atof(argv[1]);
142		/* Plan 9/GNU don't do zero */
143		if (incr == 0.0)
144			errx(1, "zero %screment", (first < last)? "in" : "de");
145	}
146
147	/* default is one for Plan 9/GNU work alike */
148	if (incr == 0.0)
149		incr = (first < last) ? 1.0 : -1.0;
150
151	if (incr <= 0.0 && first < last)
152		errx(1, "needs positive increment");
153
154	if (incr >= 0.0 && first > last)
155		errx(1, "needs negative decrement");
156
157	if (fmt != NULL) {
158		if (!valid_format(fmt))
159			errx(1, "invalid format string: `%s'", fmt);
160		fmt = unescape(fmt);
161		if (!valid_format(fmt))
162			errx(1, "invalid format string");
163		/*
164	         * XXX to be bug for bug compatible with Plan 9 add a
165		 * newline if none found at the end of the format string.
166		 */
167	} else
168		fmt = generate_format(first, incr, last, equalize, pad);
169
170	if (incr > 0) {
171		for (; first <= last; first += incr) {
172			printf(fmt, first);
173			fputs(sep, stdout);
174		}
175	} else {
176		for (; first >= last; first += incr) {
177			printf(fmt, first);
178			fputs(sep, stdout);
179		}
180	}
181	if (term != NULL)
182		fputs(term, stdout);
183
184	return (0);
185}
186
187/*
188 * numeric - verify that string is numeric
189 */
190static int
191numeric(const char *s)
192{
193	int seen_decimal_pt, decimal_pt_len;
194
195	/* skip any sign */
196	if (ISSIGN((unsigned char)*s))
197		s++;
198
199	seen_decimal_pt = 0;
200	decimal_pt_len = strlen(decimal_point);
201	while (*s) {
202		if (!isdigit((unsigned char)*s)) {
203			if (!seen_decimal_pt &&
204			    strncmp(s, decimal_point, decimal_pt_len) == 0) {
205				s += decimal_pt_len;
206				seen_decimal_pt = 1;
207				continue;
208			}
209			if (ISEXP((unsigned char)*s)) {
210				s++;
211				if (ISSIGN((unsigned char)*s) ||
212				    isdigit((unsigned char)*s)) {
213					s++;
214					continue;
215				}
216			}
217			break;
218		}
219		s++;
220	}
221	return (*s == '\0');
222}
223
224/*
225 * valid_format - validate user specified format string
226 */
227static int
228valid_format(const char *fmt)
229{
230	unsigned conversions = 0;
231
232	while (*fmt != '\0') {
233		/* scan for conversions */
234		if (*fmt != '%') {
235			fmt++;
236			continue;
237		}
238		fmt++;
239
240		/* allow %% but not things like %10% */
241		if (*fmt == '%') {
242			fmt++;
243			continue;
244		}
245
246		/* flags */
247		while (*fmt != '\0' && strchr("#0- +'", *fmt)) {
248			fmt++;
249		}
250
251		/* field width */
252		while (*fmt != '\0' && strchr("0123456789", *fmt)) {
253			fmt++;
254		}
255
256		/* precision */
257		if (*fmt == '.') {
258			fmt++;
259			while (*fmt != '\0' && strchr("0123456789", *fmt)) {
260				fmt++;
261			}
262		}
263
264		/* conversion */
265		switch (*fmt) {
266		    case 'A':
267		    case 'a':
268		    case 'E':
269		    case 'e':
270		    case 'F':
271		    case 'f':
272		    case 'G':
273		    case 'g':
274			/* floating point formats are accepted */
275			conversions++;
276			break;
277		    default:
278			/* anything else is not */
279			return 0;
280		}
281	}
282
283	return (conversions <= 1);
284}
285
286/*
287 * unescape - handle C escapes in a string
288 */
289static char *
290unescape(char *orig)
291{
292	char c, *cp, *new = orig;
293	int i;
294
295	for (cp = orig; (*orig = *cp); cp++, orig++) {
296		if (*cp != '\\')
297			continue;
298
299		switch (*++cp) {
300		case 'a':	/* alert (bell) */
301			*orig = '\a';
302			continue;
303		case 'b':	/* backspace */
304			*orig = '\b';
305			continue;
306		case 'e':	/* escape */
307			*orig = '\e';
308			continue;
309		case 'f':	/* formfeed */
310			*orig = '\f';
311			continue;
312		case 'n':	/* newline */
313			*orig = '\n';
314			continue;
315		case 'r':	/* carriage return */
316			*orig = '\r';
317			continue;
318		case 't':	/* horizontal tab */
319			*orig = '\t';
320			continue;
321		case 'v':	/* vertical tab */
322			*orig = '\v';
323			continue;
324		case '\\':	/* backslash */
325			*orig = '\\';
326			continue;
327		case '\'':	/* single quote */
328			*orig = '\'';
329			continue;
330		case '\"':	/* double quote */
331			*orig = '"';
332			continue;
333		case '0':
334		case '1':
335		case '2':
336		case '3':	/* octal */
337		case '4':
338		case '5':
339		case '6':
340		case '7':	/* number */
341			for (i = 0, c = 0;
342			     ISODIGIT((unsigned char)*cp) && i < 3;
343			     i++, cp++) {
344				c <<= 3;
345				c |= (*cp - '0');
346			}
347			*orig = c;
348			--cp;
349			continue;
350		case 'x':	/* hexadecimal number */
351			cp++;	/* skip 'x' */
352			for (i = 0, c = 0;
353			     isxdigit((unsigned char)*cp) && i < 2;
354			     i++, cp++) {
355				c <<= 4;
356				if (isdigit((unsigned char)*cp))
357					c |= (*cp - '0');
358				else
359					c |= ((toupper((unsigned char)*cp) -
360					    'A') + 10);
361			}
362			*orig = c;
363			--cp;
364			continue;
365		default:
366			--cp;
367			break;
368		}
369	}
370
371	return (new);
372}
373
374/*
375 * e_atof - convert an ASCII string to a double
376 *	exit if string is not a valid double, or if converted value would
377 *	cause overflow or underflow
378 */
379static double
380e_atof(const char *num)
381{
382	char *endp;
383	double dbl;
384
385	errno = 0;
386	dbl = strtod(num, &endp);
387
388	if (errno == ERANGE)
389		/* under or overflow */
390		err(2, "%s", num);
391	else if (*endp != '\0')
392		/* "junk" left in number */
393		errx(2, "invalid floating point argument: %s", num);
394
395	/* zero shall have no sign */
396	if (dbl == -0.0)
397		dbl = 0;
398	return (dbl);
399}
400
401/*
402 * decimal_places - count decimal places in a number (string)
403 */
404static int
405decimal_places(const char *number)
406{
407	int places = 0;
408	char *dp;
409
410	/* look for a decimal point */
411	if ((dp = strstr(number, decimal_point))) {
412		dp += strlen(decimal_point);
413
414		while (isdigit((unsigned char)*dp++))
415			places++;
416	}
417	return (places);
418}
419
420/*
421 * generate_format - create a format string
422 *
423 * XXX to be bug for bug compatible with Plan9 and GNU return "%g"
424 * when "%g" prints as "%e" (this way no width adjustments are made)
425 */
426static char *
427generate_format(double first, double incr, double last, int equalize, char pad)
428{
429	static char buf[256];
430	char cc = '\0';
431	int precision, width1, width2, places;
432
433	if (equalize == 0)
434		return (default_format);
435
436	/* figure out "last" value printed */
437	if (first > last)
438		last = first - incr * floor((first - last) / incr);
439	else
440		last = first + incr * floor((last - first) / incr);
441
442	sprintf(buf, "%g", incr);
443	if (strchr(buf, 'e'))
444		cc = 'e';
445	precision = decimal_places(buf);
446
447	width1 = sprintf(buf, "%g", first);
448	if (strchr(buf, 'e'))
449		cc = 'e';
450	if ((places = decimal_places(buf)))
451		width1 -= (places + strlen(decimal_point));
452
453	precision = MAX(places, precision);
454
455	width2 = sprintf(buf, "%g", last);
456	if (strchr(buf, 'e'))
457		cc = 'e';
458	if ((places = decimal_places(buf)))
459		width2 -= (places + strlen(decimal_point));
460
461	if (precision) {
462		sprintf(buf, "%%%c%d.%d%c", pad,
463		    MAX(width1, width2) + (int) strlen(decimal_point) +
464		    precision, precision, (cc) ? cc : 'f');
465	} else {
466		sprintf(buf, "%%%c%d%c", pad, MAX(width1, width2),
467		    (cc) ? cc : 'g');
468	}
469
470	return (buf);
471}
472